5-(unsubstituted and substituted phenoxy)-4-amino pyrimidines

ABSTRACT

The preparation of novel 5-(substituted phenoxy)-4-amino and substituted amino pyrimidines is described. These compounds, possessing anti-secretory an;d anti-ulcer activity, are effective anti-ulcer agents.

United States Patent 1 Lipinski Jan. 21, 1975 S-(UNSUBSTITUTED AND SUBSTITUTED I PIIENOXY)-4-AMINO PYRIMIDINES OTHER PUBLICATIONS 75 Inventor: Christopher Andrew Lipinski, 25973 c Budesinsky et Waterford, Conn. [73] Assignee: Pfizer Inc., New York, NY. Primary ExaminerHenry R. Jiles Assistant Examiner-S. D. Winters [22] Filed Sept 1972 Attorney, Agent, or Firm-Connolly and Hutz [21] Appl. N0.: 287,423

[52] US. CL... 260/256.4 N, 260/251 R, 260/465 F, ABSTRACT 260 4 8 D, 424 2 51] Int. Cl co'm 5 1/ 3 The substituted [58] Field of Search 260/256 4 256.4 N min) and Substituted amim pyrimidines is desmibed- These compounds, possessing anti-secretory an;d anti- [56] References Cited. ulcer activity, are effective anti-ulcer agents.

FOREIGN PATENTS OR APPLICATIONS i 5 Claims, N0 Drawings 1 2 S-(UNSUBSTITUTED AND SUBSTITUTED X PHENOXY)-4-AMINO PYRIMIDINES N BACKGROUND OF THE INVENTION 0 This invention relates to new S-(substituted phenox- 5 yJ-4-amino and substituted amino pyrimidines and to Y I their use as anti-ulcer agents. 1

Chronic gastric and duodenal ulcers, collectively wherein X Y are h hydrogcmchlmlnm known as peptic ulcers, are a common affliction for m mine alkyl cmwmmg from i Carbon hi a variety f treatments have been dcvc|upcd atoms, trlfluorornethyl or alkoxy containing from 1 to The treatment depends upon the severity of the ulcer 3 Carbon moms m the alkyl mmctyi and may range from dietary and drug treatment m Sup R, and R are each hydrogen or alkyl containing from gery. The administration ofatropine and other antichol to 6 l linergic drugs to combat gastric hyperacidity is a com- Also mcfluded f'f" are the mon treatment for peptic ulcers. Treatment with such Pharm1C6mullly'ilccepmblf2 acld Pulls as agents produces undesirable side effects such as tachyresented by h hydrochloride Mf Sulfate, cardia, mydriasis, dry skin and mouth and diarrhea. phosphmc- "mute, acetate, P l butymterate. gluconate, malate, tartratc, benzoate. succinate, An effective treatment for peptic ulcers is desirable mulemc and fumamm in which gastric anti-secretory effect is achieved by DETAILED DESCRIPTION OF THE lNvENTlON a non-anticholmergic mechanism thus avoiding the undesirable Side effects of anticholincrgic agents The compounds of this invention are related chemically to substituted pyrimidines reported in J. Org. Chem. 75, 438 970). J. Org. Chem. 26. 2770(1961), SUMMARY OF THE ENT'ON J. Am. Chem. Soc. 73, 3753 I951 and Chemical Ablt has been found that S-(substituted phen0xy)-4- stracts 49, 7606b amino and substituted amino pyrimidines of the formuk presentative of the compounds of this invention is lae below are effective inhibitors of gastric acid secrethe preparation of 4-amino-5-phenoxy pyrimidine hytion and are effective anti-ulcer agents: drochloride as shown in the following synthetic routes.

Route g Q OH OCH 0 N E ClCH C z N i 2 N HCl C) NH2 .HCl

Route g HC (NHCHO) HC oNH pTS Continued HCl ' fileilioiffiis he pr i rabi' mheirc'mte wiili il somewhat greater overall yield than Method A.

Phenoxy ethyl acetate is prepared by the procedure of J. Munch-Peterson, Acta Chem. Scand. 5, 519

The sodium salt of ethyl a'-phenoxy-B- I hydroxyacrylate is prepared by a procedure adapted from that ofT. B. Johnson and H. H. Guest, Am. Chem. J. 42, 271 (1909). Similarly, the synthesis of 2-thio-4- hydroxy-5-phenoxy pyrimidine is that reported'by T..J. Johnson and H. H. Guest, Am. Chem. J. 42, 286 1909).

The preparation of 4-hydroxy-5-phenoxy pyrimidine is accomplished by adding wet Raney-Nickel to an alkaline solution of 2-thio-4-hydroxy-5-phenoxy pyrimidine and heating at reflux for about 2 hours. The product is obtained by collecting the solid that precipitates on acidifying the filtered solution. The hydroxy compound is converted to the chloro compound by heating at about 70C. with phosphorus oxychloride, adding ammonium hydroxide to about pH 8 and extracting several times with chloroform. A colorless oil obtained on-distillation under vacuum.

4-Chloro-5-phenoxy pyrimidine is dissolved in absolute ethanol saturated with ammonia and added ammonium chloride, and heated in a stainless steel pressure bomb at about 160C. for approximately 6 hours. The ethanol is removed under vacuum, and the oily residue taken up in ether. Concentration of the ether extract gives 4-amino-5- phenoxy pyrimidine as a yellow solid which is taken up in'hot ethyl acetate, treated with activated charcoal, filtered and cooled to provide white crystals.

The phenoxy substituted compounds of this invention are prepared in analogous manner starting with appropriately substituted phenols. Substitutions in the py-' rimidine moiety are obtained by treating the 4-chloro compound with an appropriate amine.

The compounds described herein are effective antiulcer agents via the intraperitoneal and oral routes of administration against gastric ulcers. These products not only accelerate healing of such ulcers but also prevent formation of ulcers and decrease gastric acid output in animals. They can, therefore, be said to be useful for the control of peptic ulceration.

The valuable products bfifiis invention can be till ethyleneglycols' available from Carbide and Carbon Chemicals Corporation), especially Carbowax 6,000, starch, milk sugar, etc. or in capsules alone or in admixture with the same or equivalent excipients. They may also be administered orally in the form of elixirs or oral suspensions which may contain flavoring or coloring agents or be injected parenterally; that is, forexample, intramuscularly or subcutaneously. For parenteral administration, they are best used in the form of a sterile solution which may be either'aqueous such as water, isotonic saline, isotonic dextrose, Ringers solution, or non-aqueous such as fatty oils of vegetable origin (cotton seed, peanut oil, corn, sesame) and other non-.

aqueous vehicles which will not interfere with thetherapeutic efficiency of the preparation and are non-toxic in the volume or proportion used (glycerol, propylene glycol, sorbitol). Additionally, compositions suitable for extemporaneous preparation of solutions prior to administration may advantageously be made. .Sueh compositions may include liquid diluents, for example, propylene glycol, diethyl carbonate, glycerol, sorbitol,

'etc.; buffering agents as well as local anesthetics and inorganic salts to afford desirable pharmacological properties.

For both oral and intraperitoneal administration, a

dosage range of from about 150 mg. to about 300 mg.

per day is effective. The dosage level can, with careful supervision, range up to as high as about 2 grams per day. Propylene glycol is a suitable and convenient carrier or diluent forintraperitoneal use. Carbowax 6,000 is a, favored exipient for oral use. Compositions containing from about 50 percent to about 90 percent by weight of polyvinylpyrrolidone or Carbowax 6,000 are especially effective for oral administration. Higher or lower amounts of excipient can, of course, be used but appear to offer no advantages over these proprotions. For intraperitoneal use, the polyvinylpyrrolidone formulations are suspended in carriers such as water or in saline solution containing l percent carboxymethylcellulose and 0.1 percent Tween 80 (polyoxyethylene ethers of partial esters of fatty acids and hexitol anhydrides derived from sorbitol, available from' Atlas Chemical Industries, Inc.). The water soluble products of this invention are conveniently administered in Non-fasted female rats (Charles River C-D strain) weighing -l40 gms. are administered the drug or car-' rier (control animals) intraperitoneally (in saline solu tion containin g'l percent carboxymethylcellulose and 0.1 percent Tween or orally (in water) 3 hours before-being lightly anesthetized-with ether and taped in the supine position to individual sheets of acrylic plastic (Plexiglass, Rohm & Haas Co.). After recovery from the anesthesia, the restrained animals are positioned horizontally in a refrigerator maintained at ll2C. and 3 hours later sacrificed by cervical dislocation. The abdomen of each rat is opened, the pylorus clamped, the stomach inflated with saline via an oral tube. the esophagus clamped and the stomach excised. The stomachs are placed in a 0.4 percent formaldehyde solution for approximately 30 seconds to harden the outer layers and facilitate examination. Each stomach is then cut open along the greater curvature and the glandular portion (hing stomach) examined for damage. The number of gastric erosions.. their severity and the color of the stomachs is recorded. The Mann-Whitney-wilcoxon rank sum test is used to compare the median number of gastric erosions in the control group with the median number of gastric erosions in each drug-treated group to determine if they are statistically different. (Dixon et 211., lntroduction of Statistical Analysis," 3rd Ed, McGraw-Hill Book Company, New York, pp. 344-347, 1969) 7 Their effect on gastric acid output in pylorus-ligated (i.e. Shay) rats is determined by the following procedure:

Shay Rat: gms.)

48 hours before surgery female rats (Charles River C-D strain; 100-140 gms) are individually caged and taken off normal food. Each animal is given two sugar cubes and water ad libitum to effect emptying of the stomach. Drug or carrier is administered intraperitoneally and three hours later, under ether anesthesia, the abdomen is shaved and opened along the linea alba. After exposing and ligating the pylorus, the incision is closed and the animal is returned to its cage and allowed to regain consciousness. Three hours later the animal is sacrificed by cervical dislocation, the abdomen reopened, the distal esophagus clamped, and the stomach excised. The stomach is cut open and the contents washed into a beaker with 1 ml. of deionized water. The volume of gastric juice is recorded following centrifugation. Excessively dirty (greater than 0.5 ml.

EXAMPLE l Preparation of Phenoxy ethyl acetate To a suspension of 136 g. sodium ethoxide (2.0 mol) in 1500 ml. absolute ethanol was added 188 g. 2.0 mol) phenol followed by dropwise addition of 245 g (2.0 mol) ethyl chloroacetate. The mixture was heated at reflux for 18 hrs. during which time sodium chloride precipitated from solution. The reaction mixture was cooled to room temperature and filtered from insoluble salts and concentrated in vacuo to an amber oil. The filter cake was washed with ether and the ether was concentrated on a steam bath to an oil. The oils were combined and distilled to give 284 g. (78 percent) of a colorless oil, b.p. 100/4mm lit b.p/ 250/760 mm. Preparation of Sodium Salt of Ethyl a-Phenoxy-B- hydroxyacrylate To a suspension of 48 g. NaH (57 percent oil suspension 1.1 mol) in 500 ml. of anhydrous ether cooled to 8 to 10C. was added dropwise a solution of 74 g. 1.0 mol) ethyl formate, 180 g. (1.0 mol) phenoxy ethyl acetate and 100 ml. anhydrous ether. During the addition the temperature was maintained at 8 to l0by cooling in an ice bath. After the addition was completed the solution was allowed to warm to room temperature and was stirred at room temperature for 2.5 hours during which time a thick slurry ofthe product crystallized out of solution. The suspension was filtered on a Buchner funnel an dwashed well with 4:] hexane-ether and oven driedto give 1 12g. (49 percent) of at; amiss sits white solid suitable for reaction in the next step of the synthetic sequence.

Preparation of 2-Thio-4-Hydroxy-5-phenoxy pyrimidine To a suspension of 34.0 g. sodium ethoxide (0.5 mol) in 600 ml. of absolute ethanol was added 56.0 g. (0.25 mol) of the sodium salt of ethyl a-phenoxy-B- hydroxyacrylate and 38.0 g. (0.5'mo1) of thiourea. The mixture was stirred and heated at reflux for 3 hrs. One third of the volume of ethanol solvent was removed by distillation and the solution was slowly addedto an iced acetic acid solution to precipitate a white solid which was collected by vacuum filtration and oven dried to give 44.0 g. (80 percent) mp 250-253" lit mp 253-254. Preparation of 4-hydroxy 5-phenoxypyrimidine To a solution of 22.0 g. (0.55 mol) of sodium hydroxide in 700 ml. of water was dissolved 121 g. (0.55 mol) of Z-thio-4-hydroxy-5-phenoxy pyrimidine. To the stirred solution was added slowly 1250 g. of wet Raney- Nickel at such a rate that the resultant foaming remained under control. The mixture was stirred well and heated at reflux for 2 hrs. The suspension was filtered while still hot and the Raney-Nickel residue washed with 1.5 1 of boiling water with care being taken that the catalyst remained wet. The combined aqeuous solutions were concentrated to 700 ml. and acidified with acetic acid to precipitate a white solid. This was collected by filtration and oven driedto (82.5 eraeiirr'sisise'as8 Anal. ('alcd: C. 63.82;

H, 4.28; N. Found: C, 63.6 H. 4.51; N.

reduced pressure. The residue was slowly added to well stirred iced water and the residual acid was cautiously neutralized with ammonium hydroxide solution to pH 8 and was extracted with 3 X 700 ml. of chloroform. The chloroform extracts were dried over anhydrous sodium sulfate filtered and concentrated in vacuo to 85.7

. g. (9 0 ercesiisra black oil. A cortTiess'atreatiiase obtained by evaporative distillation of this material at (0.1 mm).

-Continued Anal. Calcd: C, 58.12; H. 3.42; N. 13.56; Cl. 17.16 x y R R,

Found: c. 57.83; H, 3.54; N. 13.7I;C1. 17.25

' 3-bromo S-propyH n) methyl ethyl S-isopropyl fi-lluoro hydrogen hydrogen Preparatlon of 4-amlno-5-phenoxy pyrlmldlne s-m'elhnxy hydrogen hydrogen methyl To a solution of 125 ml. of absolute ethanol saturated 5 1 hydmgc" b' 3 ethoxy 4-methyl hydrogen hydrogen with ammonia was added 2.0 g. ammonium chloride and 25.7 g. (0.124 mol) of 4-chloro-5-phenoxy pyrimidine and the mixture was heated in a 250 ml. stainless steel pressure bomb at 160 for 6 hrs. The bomb was cooled and the contents poured into a 1000 ml. rb flask. The bomb was rinsed with 4 X 100 ml. boiling TABLE 1 Antiulcer Activity in Stressed Rat Assay ethanol and the combined ethanol solutions were a solid began to precipitate. Cooling gave a yellow solid which was collected by vacuum filtration. The solid was X taken up in hot ethyl acetate and treated with activated Y stripped to an olly mixture on the rotary evaporator. N The residues were extracted with 4 X 150 ml ether and S the ether solution concentrated on the steam bath until v Dose '/1 Reduction in charcoal filtered and concentrated on the steam bath. X Y Z Roma Mg/Kg incidence OfDunwgc Careful addltlon of hexane and coollng gave 15.3 g (66 percent) white crystals mp ll8l20. H H NHz- P.0. 10 5 H H NH.( 'H; LP. 100 80 H H hflc'H-l LP. 100 60 Anal. Called: C. 6416; H.4.x5; N. 22.45 H H 35 Found: C 64.21; H. 5.02; N. 22.61

Preparation of 4-amino-5-phenoxy pyrimidine hydro- TABLE H chloride To a solution of 15.3 g. (0.082 mol) of 4-amino-5- Amisccmmryumml phenoxypyrimidine in 100 ml. of 5 percent methanol in l y 7 lnhihmm ethyl acetate was slowly added an ethyl acetate solution Dl'ise of Acid a saturated wlth HCl gas. The clear solutlon was heated X Y L MB/Kb SLLMW" on a steam bath to remove the methanol until the solu- H H NHWHCI Iv 25 I 70 tlon became sllghtly cloudy. Coollng gave 10.2 g. (1 H H l.V. 25 59 cr talline solid m 22022l. H [V 25 ll (55 percent) of whlte ys p F H NH2 W- 12-5 29 (H H NH2 |.V. 12.5 34 H H NH.('H llV. 25 80 Anal: C. 53.70; H. 4.51; N. 18.78 Found: c, 53.77; H, 4.57; N. 124.414 H H 25 '1'!) ll :1 Tltratlon m 50 percent ethanol-50 percent water gave v murn'wiwml pK,, 4.1. Infrared spectra shows the hydrochloride 40 l.\'. ll\ll';|\'|:|ltllls salt is ring protonated. The compound is soluble at 20 mg/ml in water. What is claimed is:

l. A compound selected from the group consisting of EXAMPLE H S-(unsubstituted and substituted phenoxy(-4- substi- The procedure described in Example 1 is employed to tuted amino pyrimidines of the formulae: prepare the following S-(Substituted phenoxy)-4-amino and substituted amino pyrimidines employing appropriate phenols and amines. N

C) N O N NR R NR R X and the pharmaceutically-acceptable acid addition salts,

X Y wherein X and Y are each hydrogen, chlorine. brohydrogen hydrogen methyl ethyl mine, fluorine, alkyl containing from 1 to 6 carbon hydmgc" o s trifl oromth lor alkox co 'ini 1 3-chloro hydrogen n-hexyl methyl ()0 5 b u t y h lk l ng from hydrogen 2-hromo hydrogen hydrogen to Car a m t e y y7 34mm) hydmgc" Ethyl clhy' R and R are alkyl containing from 1 to 6 carbon hydrogen 4-hromo methyl methyl hydrogen 4-lluoro n-anlyl n-zlmyl atomh' 3-vhlum Whlvm P 'PY P y 2. 4-Methylamino-S-phenoxy pyrimidine. 3-hromo S-hromo hydrogen hydrogen 3 4 5 M h hydrogen Z-methyl hydrogen hydrogen l p enoxy) py y y t y y' 4. 4-Amlno-5-(m-fluorophenoxy) pyrimidine. hydrogen 4-hexyl ethyl ethyl 5 4 D. h I 5 Il-methyl 4-ehloro hydrogen hydrogen 

2. 4-Methylamino-5-phenoxy pyrimidine.
 3. 4-Amino-5-(m-chlorophenoxy) pyrimidine.
 4. 4-Amino-5-(m-fluorophenoxy) pyrimidine.
 5. 4-Dimethylamino-5-phenoxy pyrimidine. 